Tag: externalities

Last week was a rough week for Britain. The “Beast from the East” and storm Emma swept through the country, bringing with them unusually heavy snowfall, which resulted in severe disruption across nearly all parts of the country. Some recent estimates put the cost of these extreme weather conditions at up to £1 billion per day. The construction industry suffering the biggest hit as work came to a halt for the best part of the week. Losses for the industry were estimated to be up to £2 billion.

Closed restaurants, empty shops and severely disrupted transport networks were all part of the effect that this extreme weather had on the overall economy. According to Howard Archer, chief economic adviser of the EY ITEM Club (a UK forecasting group):

It is possible that the severe weather [of the last few days] could lead to GDP growth being reduced by 0.1 percentage point in Q1 2018 and possibly 0.2 percentage points if the severe weather persist.


Source: Jahn (2015), Figure 2

As the occurrence of freak weather increases across the globe due to climate change, so does the economic cost of these events. The figure above shows the estimated costs of extreme weather events in the USA between 1980 and 2012 and it is reproduced from Jahn (see link below), who also fits a quadratic trend to show that these costs have been increasing over time. He goes on to characterise the impact of different types of extreme weather (including cold waves, heat waves, storms and others) on different sectors of the local economy – ranging from tourism and agriculture, to housing and the insurance sector.

Linnenluecke et al (linked below) argue that extreme weather caused by climate change could influence the decision of firms on where to locate and could lead to a reshuffle of economic activity across the world and have important policy implications. As the authors explain:

Climate change-related relocation has been given consideration in policy-oriented discussions, but not in management decisions. The effects of climate change and extreme weather events have been considered as peripheral or as a risk factor, but not as a determining factor in firm relocation processes…. This paper therefore [provides] insights for understanding how firms can enhance strategic decision-making in light of understanding and assessing their vulnerability as well as likely impacts that climate change may have on relocation decisions.

The likelihood and associated costs of extreme weather events could therefore become an increasingly important matter for discussion amongst economists and policy makers. Such weather events are likely to have profound economic implications for the world.

Academic papers



  1. Explain how extreme weather can affect the decision of firms to locate between regions.
  2. Explain how extreme weather can affect the behaviour of consumers and the level of consumer spending.
  3. “The poorest countries are often the ones that are the most vulnerable to the effects of climatic change”. Discuss.

The linked articles below look at the state of the railways in Britain and whether renationalisation would be the best way of securing more investment, better services and lower fares.

Rail travel and rail freight involve significant positive externalities, as people and goods transported by rail reduce road congestion, accidents and traffic pollution. In a purely private rail system with no government support, these externalities would not be taken into account and there would be a socially sub-optimal use of the railways. If all government support for the railways were withdrawn, this would almost certainly result in rail closures, as was the case in the 1960s, following the publication of the Beeching Report in 1963.

Also the returns on rail investment are generally long term. Such investment may not, therefore, be attractive to private rail operators seeking shorter-term returns.

These are strong arguments for government intervention to support the railways. But there is considerable disagreement over the best means of doing so.

One option is full nationalisation. This would include both the infrastructure (track, signalling, stations, bridges, tunnels and marshalling yards) and the trains (the trains themselves – both passenger and freight – and their operation).

At present, the infrastructure (except for most stations) is owned, operated, developed and maintained by Network Rail, which is a non-departmental public company (NDPB) or ‘Quango’ (Quasi-autonomous non-governmental organisation, such as NHS trusts, the Forestry Commission or the Office for Students. It has no shareholders and reinvests its profits in the rail infrastructure. Like other NDPBs, it has an arm’s-length relationship with the government. Network Rail is answerable to the government via the Department for Transport. This part of the system, therefore, is nationalised – if the term ‘nationalised organisations’ includes NDPBs and not just full public corporations such as the BBC, the Bank of England and Post Office Ltd.

Train operating companies, however, except in Northern Ireland, are privately owned under a franchise system, with each franchise covering specific routes. Each of the 17 passenger franchises is awarded under a competitive tendering system for a specific period of time, typically seven years, but with some for longer. Some companies operate more than one franchise.

Companies awarded a profitable franchise are required to pay the government for operating it. Companies awarded a loss-making franchise are given subsidies by the government to operate it. In awarding franchises, the government looks at the level of payments the bidders are offering or the subsidies they are requiring.

But this system has come in for increasing criticism, with rising real fares, overcrowding on many trains and poor service quality. The Labour Party is committed to taking franchises into public ownership as they come up for renewal. Indeed, there is considerable public support for nationalising the train operating companies.

The main issue is which system would best address the issues of externalities, efficiency, quality of service, fares and investment. Ultimately it depends on the will of the government. Under either system the government plays a major part in determining the level of financial support, operating criteria and the level of investment. For this reason, many argue that the system of ownership is less important than the level and type of support given by the government and how it requires the railways to be run.


The case for re-nationalising Britain’s railways The Conversation, Nicole Badstuber (27/8/15)
Lessons from the Beeching cuts in reviving Britain’s railwa The Conversataion, Andrew Edwards (7/12/17)
Britain’s railways were nationalised 70 years ago – let’s not do it again The Conversation, Jonathan Cowie (1/1/18)
FactCheck Q&A: Should we nationalise the railways? Channel 4 News, Martin Williiams (18/5/17)
Britain’s railways need careful expansion, not nationalisation Financial Times, Julian Glover (5/1/18)
Right or wrong, Labour is offering a solution to the legitimacy crisis of our privatised railways Independent. Ben Chu (2/1/18)
Whether or not nationalisation is the answer, there are serious questions about the health of Britain’s railways Independent. Editorial (2/1/18)
Why Nationalising The Railways Is The Biggest Misdirect In Politics Huffington Post, Chris Whiting (5/1/18)


  1. What categories of market failure would exist in a purely private rail system with no government intervention?
  2. What types of savings could be made by nationalising train operating companies?
  3. The franchise system is one of contestable monopolies. In what ways are they contestable and what benefits does the system bring? Are there any costs from the contestable nature of the system?
  4. Is it feasible to have franchises that allow more than one train operator to run on most routes, thereby providing some degree of continuing competition?
  5. How are rail fares determined in Britain?
  6. Would nationalising the train operating companies be costly to the taxpayer? Explain.
  7. What determines the optimal length of a franchise under the current system?
  8. What role does leasing play in investment in rolling stock?
  9. What are the arguments for and against the government’s decision in November 2017 to allow the Virgin/Stagecoach partnership to pull out of the East Coast franchise three years early because it found the agreed payments to the government too onerous?
  10. Could the current system be amended in any way to meet the criticisms that it does not adequately take into account the positive externalities of rail transport and the need for substantial investment, while also encouraging excessive risk taking by bidding companies at the tendering stage?

In 2012, the Scottish Parliament voted to introduce a minimum unit price for alcoholic drinks. The Scotch Whisky Association along with others appealed against the legislation, but on 15 November 2017 the UK Supreme Court ruled unanimously that the legislation does not breach European Union law. It is thus likely that, after consultation, a 50p minimum unit price will be introduced, making Scotland the first country in the world to introduce minimum pricing for alcohol.

As we saw in a previous blog, Alcohol minimum price, the aim is to prevent the sale of really cheap drinks in supermarkets and other outlets. For example, three-litre bottles of strong cider can be sold for as little as £3.59. Sometimes supermarkets offer multibuys which are heavily discounted. The idea of minimum pricing is to stop these practices without affecting ‘normal’ prices. For example, the legislation will not affect prices in pubs, which are already more than 50p per unit of alcohol.

The following table shows how much prices would rise for various types of drink when compared to current cheap supermarket prices. The biggest percentage effect is for cheap, strong cider and beer.

Strength Size Units of alcohol Current price New minimum price
Cheap strong cider 7.5% 3 litres 22.5 £3.50 £11.25
Cheap wine 13% 750ml 9.75 £3.99 £4.88
Cheap beer/lager (normal) 4% 4 × 440ml 7.04 £2.50 £3.52
Cheap beer/lager (strong) 8% 4 × 500ml 16 £3.50 £8.00
Cheap spirits 37.5% 70cl 26.25 £10.00 £13.13
Cheap strong spirits 50% 70cl 35 £12.00 £17.50

The hope is that by preventing the sale of really cheap drinks in supermarkets, people will no longer be encouraged to ‘pre-load’, so that when they go out for the evening they are already drunk. It would also help to reduce the number of alcoholics amongst the poor.

But this raises the question of equity. By targeting cheap drink, the policy is likely to hit the poor hardest. The question is whether this will simply lead to alcoholics on low incomes cutting down on other things, such as food and clothing for themselves and their children.

How successful, then, will such a policy be in cutting down drunkenness and the associated anti-social behaviour in many Scottish towns and cities, especially on Friday and Saturday nights? This will depend on the price elasticity of demand.

Videos and podcasts

Scotland first country to introduce minimum alcohol price Channel 4 News, Fatima Manji (15/11/17)
The story of how Scotland brought in minimum pricing on alcoh The Scotsman, Ross McCafferty (15/11/17)
Supreme Court rejects challenge against plans for minimum alcohol pricing in Scotland ITV News, Peter Smith (15/11/17)
Scotland getting the all-clear for minimum alcohol pricing as judges reject appeal Heart Scotland News, Connor Gillies (15/11/17)


Alcohol minimum unit pricing to go ahead Scottish Government: news (15/11/17)
Scottish alcohol price survey 2016 Alcohol Focus Scotland (2016)
Minimum pricing Alcohol Focus Scotland (2017)
Supreme Court backs Scottish minimum alcohol pricing BBC News (15/11/17)
Supreme Court backs Scottish minimum alcohol pricing plans Out-Law.com (15/11/17)
Go-ahead for minimum alcohol pricing British Medical Association (BMA), Jennifer Trueland (15/11/17)
Expert reaction to UK supreme court ruling that the Scottish government can set a minimum price for alcohol, rejecting a challenge by the Scotch Whisky Association Science Media Centre (15/11/17)
Scotland to become first country with minimum price for alcohol sales Independent, Alex Matthews-King (15/11/17)
Scotland leading the world over minimum alcohol price ITV News (15/11/17)
Campaigners urge minimum alcohol price in England after Scottish ruling The Guardian, Severin Carrell (15/11/17)
Scottish ‘booze cruises’ to England predicted as minimum pricing introduced The Telegraph, Olivia Rudgard (15/11/17)


  1. Draw a diagram to illustrate the effect of a minimum price per unit of alcohol on (a) cheap cider; (b) good quality wine.
  2. What would be the likely effects of a 50p per unit minimum price on the pub trade?
  3. How is the price elasticity of demand for alcoholic drinks relevant to determining the success of minimum pricing?
  4. What determines the price elasticity of demand for cheap alcoholic drinks?
  5. Compare the effects on alcohol consumption of imposing a minimum unit price of alcohol with raising the duty on alcoholic drinks. What are the revenue implications of the two policies for the government?
  6. What externalities are involved in the consumption of alcohol? How could a socially efficient price for alcohol be determined?
  7. Could alcohol consumption be described as a ‘de-merit good’? Explain.
  8. Other than high minimum prices and taxation, what other policies could be used to (a) tackle binge drinking; (b) tackle the problem of alcoholism?
  9. What will determine the number of people travelling from Scotland to England to buy cheaper alcoholic drinks?

With first Houston, then several Caribbean islands and Florida suffering dreadful flooding and destruction from Hurricanes Harvey and Irma, many are questioning whether more should be spent on flood prevention and reducing greenhouse gas emissions. Economists would normally argue that such questions are answered by conducting a cost–benefit analysis.

However, even if the size of the costs and benefits of such policies could be measured, this would not be enough to give the answer. Whether such spending is justified would depend on the social rate of discount. But what the rate should be in cost-benefit analyses is a highly contested issue, especially when the benefits occur a long time in the future.

I you ask the question today, ‘should more have been spent on flood prevention in Houston and Miami?’, the answer would almost certainly be yes, even if the decision had to have been taken many years ago, given the time it takes to plan and construct such defences. But if you asked people, say, 15 years ago whether such expenditure should be undertaken, many would have said no, given that the protection would be provided quite a long time in the future. Also many people back then would doubt that the defences would be necessary and many would not be planning to live there indefinitely.

This is the familiar problem of people valuing costs and benefits in the future less than costs and benefits occurring today. To account for this, costs and benefits in the future are discounted by an annual rate to reduce them to a present value.

But with costs and benefits occurring a long time in the future, especially from measures to reduce carbon emissions, the present value is very sensitive to the rate of discount chosen. But choosing the rate of discount is fraught with difficulties.

Some argue that a social rate of discount should be similar to long-term market rates. But market rates reflect only the current generation’s private preferences. They do not reflect the costs and benefits to future generations. A social rate of discount that did take their interests into account would be much lower and could even be argued to be zero – or negative with a growing population.

Against this, however, has to be set the possibility that future generations will be richer than the current one and will therefore value a dollar (or any other currency) less than today’s generation.

However, it is also likely, if the trend of recent decades is to continue, that economic growth will be largely confined to the rich and that the poor will be little better off, if at all. And it is the poor who often suffer the most from natural disasters. Just look, for example, at the much higher personal devastation suffered from hurricane Irma by the poor on many Caribbean islands compared with those in comparatively wealthy Florida.

A low or zero discount rate would make many environmental projects socially profitable, even though they would not be with a higher rate. The choice of rate is thus crucial to the welfare of future generations who are likely to bear the brunt of climate change.

But just how should the social rate of discount be chosen? The following two articles explore the issue.


How Much Is the Future Worth? Slate, Will Oremus (1/9/17)
Climate changes the debate: The impact of demographics on long-term discount rates Vox, Eli P Fenichel, Matthew Kotchen and Ethan T Addicott (20/8/17)


  1. What is meant by the social rate of discount?
  2. Why does the choice of a lower rate of social discount imply a more aggressive climate policy?
  3. How is the distribution of the benefits and costs of measures to reduce carbon emissions between rich and poor relevant in choosing the social rate of discount of such measures?
  4. How is the distribution of the benefits of such measures between current and future generations relevant in choosing the rate?
  5. How is uncertainty about the magnitude of the costs and benefits relevant in choosing the rate?
  6. What is the difference between Stern’s and Nordhaus’ analyses of the choice of social discount rate?
  7. Explain and discuss the ‘mortality-based approach’ to estimating social discount rates.
  8. What are the arguments ‘for economists analysing climate change through the lens of minimising risk, rather than maximizing utility’?

According to Christine Lagarde, Managing Director of the IMF, the slow growth in global productivity is acting as a brake on the growth in potential income and is thus holding back the growth in living standards. In a recent speech in Washington she said that:

Over the past decade, there have been sharp slowdowns in measured output per worker and total factor productivity – which can be seen as a measure of innovation. In advanced economies, for example, productivity growth has dropped to 0.3 per cent, down from a pre-crisis average of about 1 per cent. This trend has also affected many emerging and developing countries, including China.

We estimate that, if total factor productivity growth had followed its pre-crisis trend, overall GDP in advanced economies would be about 5 percent higher today. That would be the equivalent of adding another Japan – and more – to the global economy.

So why has productivity growth slowed to well below pre-crisis rates? One reason is an ageing working population, with older workers acquiring new skills less quickly. A second is the slowdown in world trade and, with it, the competitive pressure for firms to invest in the latest technologies.

A third is the continuing effect of the financial crisis, with many highly indebted firms forced to make deep cuts in investment and many others being cautious about innovating. The crisis has dampened risk taking – a key component of innovation.

What is clear, said Lagarde, is that more innovation is needed to restore productivity growth. But markets alone cannot achieve this, as the benefits of invention and innovation are, to some extent, public goods. They have considerable positive externalities.

She thus called on governments to give high priority to stimulating productivity growth and unleashing entrepreneurial energy. There are several things governments can do. These include market-orientated supply-side policies, such as removing unnecessary barriers to competition, driving forward international free trade and cutting red tape. They also include direct intervention through greater investment in education and training, infrastructure and public-sector R&D. They also include giving subsidies and/or tax relief for private-sector R&D.

Banks too have a role in chanelling finance away from low-productivity firms and towards ‘young and vibrant companies’.

It is important to recognise, she concluded, that innovation and structural change can lead to some people losing out, with job losses, low wages and social deprivation. Support should be given to such people through better education, retraining and employment incentives.


IMF chief warns slowing productivity risks living standards drop Reuters, David Lawder (3/4/17)
Global productivity slowdown risks social turmoil, IMF warns Financial Times, Shawn Donnan (3/4/17)
Global productivity slowdown risks creating instability, warns IMF The Guardian, Katie Allen (3/4/17)
The Guardian view on productivity: Britain must solve the puzzle The Guardian (9/4/17)

Reinvigorating Productivity Growth IMF Speeches, Christine Lagarde, Managing Director, IMF(3/4/17)

Gone with the Headwinds: Global Productivity IMF Staff Discussion Note, Gustavo Adler, Romain Duval, Davide Furceri, Sinem Kiliç Çelik, Ksenia Koloskova and Marcos Poplawski-Ribeiro (April 2017)


  1. What is the relationship between actual and potential economic growth?
  2. Distinguish between labour productivity and total factor productivity.
  3. Why has total factor productivity growth been considerably slower since the financial crisis than before?
  4. Is sustained productivity growth (a) a necessary and/or (b) a sufficient condition for a sustained growth in living standards?
  5. Give some examples of technological developments that could feed through into significant growth in productivity.
  6. What is the relationship between immigration and productivity growth?
  7. What policies would you advocate for increasing productivity? Explain why.